In view of the difficulty and complexity involved in transferring rectilinear to rotary force in the standard internal combustion engine, a number of approaches have been presented to provide a rotary internal combustion engine, thus eliminating this aggravating problem.
Most commonly, to provide the necessary function of fuel intake, compression, combustion and ultimate exhaust, these engines have included a housing having an internal wall in the form of a two-lobe epitrochoid within which a multi-lobe rotor is supported for eccentric rotation thus to provide a multiplicity of working chambers in which the various functions can occur with appropriate association with carburetors, distributors, spark plugs, and intake and exhaust manifolds. The configuration both of the housing (stator) and the rotor together with its manner of mounting has provided initial cost which was relatively high, a subsequent maintenance expense which was equally great, and an ultimate requirement for frequent overhaul.
As an alternate approach, the housing has been provided with a cylindrical interior wall within which the multi-lobe rotor is arranged to rotate but with an attendant complex valve arrangement to provide the requisite compression and subsequent expansion function with resultant initial high cost as well as excessive maintenance and repair expense subsequently.